Anchor device for well tools



May

Filed April 12,

9, 1967 M. B. CONRAD ANCHOR DEVICE FOR WELL TOOLS 3 Sheets-Sheet 1INVENTOR. MART/N B. GOA/A340 ATTOR/VEVS May 9, 1967 M. B. CONRAD ANCHORDEVICE FOR WELL TOOLS Filed April 12, 1966 5 Sheets-Sheet 2 z mhllllilMay 9, 1967 Filed April 12, 1966 M. B. CONRAD ANCHOR DEVICE FOR WELLTOOLS Mae ff 3 Sheets-Sheet, 5

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crr/ Q INVENTOR MAPWA/ B. CONEAD United States Patent 3,318,385 ANCHORDEVICE FOR WELL TOOLS Martin B. Conrad, PO. Box 568, Carpinteria, Calif.93013 Filed Apr. 12, 1966, Ser. No. 549,096 18 Claims. (Cl. 166-212)This is a continuation-in-part of my copending patent application Ser.No. 311,397, filed Sept. 25, 1963, now abandoned, for Anchor Device forWell Tools.

This invention relates to subsurface well tools and is particularlydirected to a friction or shear anchor device adapted for operationwithin a well casing.

The principal object of this invention is to provide an improved form ofanchor device which may be set and released by fluid pressure.

Another object is to provide a device of this type which is relativelyshort in length and which is capable of successful operation in shallowholes.

Another object is to provide such a device which operates solely byfrictional contact with the casing, or which may be equipped withgripping elements having wicker teeth to bite into the inner surface ofthe casing.

Another object is to provide a device of this type employing anexpansible, elastomeric sleeve together with a novel form of slottedcasing-engaging member expansible into contact with the casing whenfluid pressure is supplied within the sleeve.

Another object of this invention is to provide an anchor deviceutilizing an expansible sleeve for moving a casing-engaging memberoutwardly into contact with the casing, while having a means to preventa gap from opening at the end of the casing-engaging member throughwhich the sleeve could extrude.

Other and more detailed objects and advantages will appear hereinafter.1

In the drawings:

FIGURE 1 is a longitudinal sectional view showing a preferred embodimentof this invention, the parts being in retracted, inoperative position;

FIGURE 2 is a perspective view of the casing-contacting member;

FIGURE 3 is a perspective view of the backing member;

FIGURE 4 is a sectional view taken substantially on the lines 44 asshown in FIGURE 1;

FIGURE 5 is a sectional view taken substantially on the lines 55 asshown in FIGURE 1;

FIGURE 6 is a sectional detail showing the parts in casing-engagingposition;

FIGURE 7 is a perspective view showing a modified form ofcasing-contacting member;

FIGURE 8 is a perspective view showing a modified form of backing memberfor use with the device shown in FIGURE 6;

FIGURE 9 is a sectional detail showing another modification;

FIGURE 10 is a longitudinal sectional view of the anchor embodying amodified arrangement for eliminating clearances at the ends of theeXpansible assembly, with the anchor in the retracted position;

FIGURE 11 is an enlarged fragmentary longitudinal sectional view of oneside of the anchor assembly of FIGURE 10, with the anchor expanded togrip the easing; and

FIGURE 12 is a view similar to FIGURE 11 but with a different means forclosing out the gap at the ends of the expansible assembly.

Referring to the drawings, a tubular body generally designated 10 isadapted to be lowered into a well casing 11 on a tubing string 12. Thetubular body 10 includes an axial cylindrical mandrel 113, provided withan in- Ice tegral ring 14 at its upper end. At its lower end the mandrel1-3 is connected by threads 15 to the tubular part 16. The ring 14 has askirt 17 and a downwardfacing abutment 18, while the tubular part 16 hasan upward-facing abutment 19.

Mounted on the tubular body 10 and encircling the mandrel 13 between theabutments 18 and 19 is an expansible assembly generally designated 20.This assembly includes an elastomeric sleeve 22 encircling the mandrel13, a casing-contacting member 23, and a backing member 24 interposedbetween the sleeve 22 and the member 23. The upper end of theelastomeric sleeve 22 is enlarged and extends into a. recess 25 providedin the upper collar 26. Similarly, the lower end of the elastomericsleeve 22 is enlarged and is received within the recess 27 of the lowercollar 28. The upper collar 26 is engaged by the abutment 18 and forms asliding seal with the inner cylindrical surface of the skirt 17, theseal ring 29 serving to prevent leakage. The upper collar 26 has adownward-facing abutment shoulder 30. The lower collar 28 rests on theabutment 19 and forms a sliding seal with the outer surface of themandrel 13, the seal ring 31 serving to prevent leakage. The lowercollar 28 has an upward-facing shoulder 32. The casing-engaging member23 and the backing member 24 are each confined between the shoulders 30and 32 on the collars 26 and 28. Lips 33 and 34 on the collars 26 and 28limit outward expanding movement of the easing-engaging member 23.

The casing-engaging member 23 is formed as a tubular member and isprovided with two series of longitudinal slots 37 and 38. The slots 37extend from the upper end and terminate short of the lower end; theslots 38 extend from the lower end and terminate short of the upper end.Thus, adjacent slots extend from opposite ends of the member 23 anddefine between the slots a series of circumferentially adjacent grippingelements 39. The slots are equally spaced and the gripping elements 39are of equal width. The outer surface of the member 23 is provided withlongitudinal grooves 40 which extend for substantially the full lengthof the member 23 and intersect the beveled surfaces 41. The slottedconstruction of the casing-engaging member 23 provides for substantiallyequal outward movement of the gripping elements 39, under uniforminternal expansion force.

The backing member 24 is formed in a similar manner to thecasing-engaging member 23 and is also provided with two series oflongitudinal slots 45 and 46, the slots 45 extending from the lower end.The member 24 is provided with a radial pin 47, which is adapted toslide into one of the slots 38 on the member 23 when the backing member24 is positioned within the casing-engaging member 23, in order tostagger the slots in one member with respect to the slots in the other.In this way, the material of the elastomeric sleeve 22 i prevented fromextruding outward through the slots 37 and 38 in the easing-engagingmember 23.

A plurality of ports 50 are provided in the mandrel 13 near its upperend. These ports communicate with the space 51 within the upper collar26. The ports 50 also communicate by way of clearance space 51a andmilled grooves 52 in the outer surface of the mandrel 13 with the innersurface of the elastomeric sleeve 22. The small clearance space 51aprevents extrusion of the elastomeric sleeve 22 under externalpressures, and the milled grooves 52 insure that pressure fluid from theports 50 reaches the interior of the elastomeric sleeve. Accordingly,when the pressure of fluid inside the tubular body 10 and mandrel '13exceeds the fluid pressure within the casing 11, fluid under pressurepasses from the interior of the mandrel 13 through the ports 50 andthrough the milled grooves into the interior of the elastomeric sleeve22. The sleeve 22 expandsqradially, and the backing member 24 andcasingeng-aging member 23 are expanded thereby. The gripping elements 39defined between slots 37 and 38 move outward along the shoulders 30 and32 of the upper and lower collars 26 and 28, until the smooth outersurfaces of the gripping elements 39 engage the inner surface of thecasing 11'. Fluid pressure within the space 51 acts on the upper end ofthe collar 26 and causes it to move downward with respect to the mandrel13 to absorb any tension elongation of the mandrel 13 and to maintaintheshoulders 30 and 32 in contact with the members 23 and 24. Theexposed area of the sleeve 26 to the pressure fluid admitted 7 throughthe ports 50 is greater above the sleeve than below it.

This feature of the invention performs a valuable function in thesuccessful operation of the anchor device of this invention bypreventing extrusion of the elastomeric sleeve 22. With thefluidpressure urging the collar 26 downwardly, the shoulder 30 willalways maintain its con tact, with theupper ends of the members 23 and24. This is despite the elongation of the mandrel 13 that will occurfrom the forces imposed upon it.

This effect can be seen in FIGURE 6, where the mandrel has experiencedsome elongation resulting from pressures applied to it. The collar 26has moved downwardly because of the net piston area at its upper. endwhich is sealed at its outer periphery by the O-ring 29. The shoulder 39of the-collar 2 6, consequently, is held against the upper ends of themembers 23 and 24.

With the collar 26 held in engagement with the ends of pull on themandrel is transmitted through the shoulder 32 of the lower collar 28 tothe bottomend of the mem-' ber 23; Extrusion of the sleeve 22 throughsuchfa gap at. the upper end of the assembly 20, of course,v would causemalfunction of the anchor.

In operation, the tubular member 10 is lowered into the 'casing'll withthe parts in position as shown in FIGURE 1; The. longitudinal grooves401in the casing engaging member 23 serve as passages for fluid withinthe casing.

The assembly 20 may be employed to anchor the lower end'of the tubingstring '12 with respect-to the casing for any desired purpose. Anothertool, for example, are-v trievable bridge plug, may be carried on thetubing string 12 above or below the tubular member 10. When the devicerea'chesthe desired elevation within the casing 11, the. pressure insidethe'tubing 'string 12 is increased, thereby causing fluid under pressureto enter the annular space between the mandrel 13 and the elastomericsleeve 22.

The pressure of the fluid acts to move'the gripping elements 39 of theslotted member, 23. into engagement with the inner surface ofthe casing,as shown in FIGURE 6. The parts 13, 23, and 24 are formed of metal,preferably steel, so that they have sufiicient resilience to contract totheir initial :shape when theqpressureis equalized inside and outsidethe elastomeric sleeve 22..

In a modified form of my invention shown in FIG- and 8, thecasing-engaging member 23a and the backing member 24aare similar to thatpreviously described except that the slots are located in diflerentpositions; Two series of slots are. provided; the slots 38a extend forthe major portion of the length of the member 23a but terminate short ofthe ends thereof, and the slots 37a in the other series. each comprisealigned slot portions extendingfromthe extreme ends of the member 23abut terminate short of the mid-portion thereof. The gripping elements39a are defined between adjacent slots 37a and 38a. The slots 45a and46a in the backing member 24a are similar to the slots 37a and 38a,respectively. The radial pin 47a enters one of the slots 37a and thecasingengaging member 23a, to hold the slots in the members 23a and 24ain staggered relationship.

In the modified form of the invention shown in FIG- URE 9, wicker teethare provided on the outer surfaces of the gripping elements 3%. Thewicker teeth 55 are preferably located on a cylindrical surface ofsmaller diameter than the diameter of the cylindrical defined by theends 56 of the elements 39a. In this way, the wicker teeth are protectedagainst dragging contact with the interior surface of the casing 11 asthe device is lowered into the well.

When the gripping elements 3% are expanded by means of thepressure-energized elastomeric sleeve 22, however, the elements 39belastically deform and bow sufficiently to engage the wicker teeth 55into the inner surface of the casing 11. The wicker teeth bite into thecasing and hence a shear resistance load as well as a friction loadopposes longitudinal movement of the anchor device Within the casing 11.The device ofFIG- URE 9 may employ a casing-engaging member and backupmember of the form shown in FIGURES 2 and 3 or FIGURES 7 and 9.

When the outside surfaces of the gripping elements 39 are smooth, theanchor device may be employed as a drag-block assembly. The unstressedfree-diameter of the gripping elements may be made larger than theinside diameter of the casing, and in this Way, a friction drag forcemay be provided and without actually anchoring the device againstlongitudinal movement.

' Although the slots in the members 23, 24, 23a, and 24a are shown inthe drawings as extending axially of the members, it is to be understoodthat this is by way of illustration only, and the slots operatesatisfactorily even though they may have some inclination or helicallead. The word longitudinal as used in connection withithese slots inthe specification and claims applies to slots which are axial or whichhave a helical lead with axsubstantial longitudinal component. I

As an example of relative sizes of parts which may be usedin carryingout this invention, the casing-contacting member may have an outsidediameter when unstressed of 3.795" for contacting the inside surface of4 /2" casing,

and the inside diameter may be'-3.06 2". The grooves may be /2" wide andA" deep. The slots may be from to A." wide. The backing member may be3.062 'outside diameter and 2.875" inside diameter, and the slot may beto, /s" wide. All of these dimensions are approximate. When the partsare made of steel with these. diameters and thicknesses, they contractto initial unstressed size after pressure is released within theelastomericsleeve, and with substantially no permanent deformation.-

The embodiment of the invention illustrated in FIG- URES 10 and 11provides a modified arrangement for eliminating any clearances at theends of the expansib'le assembly 20 to assure retention of theelastomeric sleeve. In the construction of FIGURES 10 and 11, thepressure from the fluid reacts against the movable collar through a beadat the end of the expansible sleeve, rather than directly contacting thecollar as for the collar 26 in the design of FIGURE 1. This eliminatesthe need for a seal around the outer periphery of the movable collar.

As shown in FIGURES'IO and 11, a short tubular member 57 is threadedonto the bottom end of the tubing string 12 and connects by threads, inturn, to the upper end of a cylindrical body in the form of a mandrel58. The bottom end of the mandrel 58 is threadably connected to adepending tubular element 59. The mandrel 58 has upper and lower sets ofopenings 60 and 61, respectively, that provide communication between thebore of the mandrel and the interior of an elastomeric sleeve 62 thatcorresponds to the sleeve 22 of the previously described embodiment. Theexpansible assembly 20, which includes the casing-contacting member 23and the backing member 24, circumscribes the sleeve 62.

At the ends of the assembly 20 are collars 64 and 6 having radialshoulders 66 and 67 for engaging the ends of the members 23 and 24.Above the radial shoulder 67, the collar 64 includes a downwardly andinwardly inclined surface 68 from the upper ends of which projects anaxially directed flange portion 69. Similarly, the collar 65 has anupwardly and inwardly inclined surface 70 and a flange portion 71extending downwardly from this surface.

The tubular member 57 above the collar 64 has a downwardly and outwardlyinclined end surface 73 that is convergent with the surface 68 of thecollar 64 and extends to the inner wall of the flange 69 just above thesurface 70. The outer periphery of the tubular member 57 is recessed toreceive the flange 69, which is engaged by a shoulder 74 on the member57. Therefore, when the member 57 is threaded into place so that itsinner shoulder 75 bottoms against the upper end of the mandrel 58, thecollar 64 is retained between the shoulder 74 of the member 57 and theupper end of the expansible assembly 20.

The bottom portion of the anchor is generally the same, with adownwardly inclined surface 76 on the member 59 extending from theflange portion 71 of the lower collar 65. The lower tubular member 59 isthreaded onto the mandrel until its inner shoulder 77 engages the bottomend of the mandrel, which thereby retains the collar 65 between theouter shoulder 78 of the lower tubular member 59 and the bottom end ofthe expansible assembly 20. The collars 64 and 65, together with theshoulders 74 and 78 of the tubular members 57 and 59, position themembers 23 and 24 axially of the mandrel 58.

The elastomeric sleeve 62 is provided with an annular rib or beadportion 79 extending into the wedge-shaped space defined between thesurfaces 73 and 68 of the members 57 and 64, respectively. A similarannular rib 80 is received between the surface 76 of the lower tubularmember 59 and the inclined surface 70 of the collar 65. Additional smallend beads 81 and 82 on the sleeve 62 fit in recesses in the members 57and 59, respectively. Thus, the ends of the sleeve 62 are retained.

Operation of the anchor in the embodiment of FIG- URES and 11 isbasically the same as that described above. Fluid pressure within themandrel 58 has access through the openings 60 and 61 to the inside ofthe sleeve 62, thereby expanding the assembly to frictionally engage thecasing 11. This locks the anchor in position. However, the fluidpressure does not act directly upon the end of a piston in taking up theclearance at the ends of the expansible assembly 20 when elongation ofthe mandrel occurs. The fluid pressure from within the sleeve 62 willforce the upper rib portion 79 tightly into the space between thesurfaces 68 and 73. The resilient rib 79 of the sleeve 62 transmits thefluid pressures to the inclined surface 68 of the collar 64. Thisproduces a downward reaction on the collar 64, forcing it against theupper end of the assembly 20. Therefore, as may be seen in the enlargedillustration of FIGURE 11 where the mandrel has experienced someelongation, the collar 64 is shifted downwardly by the force imposedupon it by the rib 79 of the sleeve 62, which in turn receives thepressure applied to the interior of the mandrel 58. This downwardmovement of the collar 64 takes up the end clearance so that a gap willnot open up at the upper end of the assembly 20, and the sleeve 62 willnot be extruded outwardly.

A similar result is obtained at the lower end of the anchor, where thefluid pressure forces the rib. 80 against 6 the surfaces 70 of thecollar 65. This holds the radial shoulder 67 of the collar 65 in contactwith the shoulder formed by the bottom end of the assembly 20. Again,zero clearance is maintained and the sleeve is retained againstextrusion.

As the invention is illustrated in FIGURES 10 and 11, there is aprovision for eliminating a gap at either end of the assembly 20, sothat the anchor is designed to withstand both upward and downward loads.In the embodiment of FIGURE 1, the device is intended to be under a pullfrom'above, so that only the upper collar 26 in that arrangement isprovided with a piston area to take out the end clearance. The load onthe bottom collar 28 necessarily will hold the abutment shoulder 32 inengagement with the bottom end of the assembly 20. Consequently, thereis no need for a means to take out clearances at that location. However,the design of FIGURE 1 readily could be constructed for withstandingloads in two directions by making the collar 28 similar to the uppercollar 26.

In the illustration of FIGURE 11, the anchor is shown in a conditionwhere no end load is applied, and both collars 66 and 67 have beencaused to move inwardly with respect to the expansible assembly 20. Thisis for purposes of illustration, indicating how clearances areeliminated at the two ends of the assembly 20. Normally, however, therewill be a load either upwardly or downwardly on the unit, so that onlyone of the collars will move inwardly. The other collar then willtransmit the axial loads from the mandrel to the expansible assembly 20.For upward loads, the forces are transferred from the mandrel throughthe shoulder 78 of the tubular member 59 to the flange 71 of the lowercollar 65, and from the latter member to the bottom end of thecasingengaging member 23. Similarly, downward loads are taken outthrough the shoulder 74 of the upper tubular member 57 to the flange 69of the collar 64, and through the collars shoulder 66 to the upper endof the member 23.

In the embodiment of FIGURE 12, there is no moving collar on the anchor,but nevertheless end clearances are eliminated, so that the sleeve isfully supported throughout its length. In this construction, the anchorelement is made to bend, which elongates it in the direction of themandrel axis so that a gap does not occur when the mandrel stretches.The elastomeric sleeve 83 is held at its upper end by a fixed collar 84that threads onto the upper end of the mandrel 85. An annular rib 86 onthe member 84 fits into a complementary recess at the end of the sleeve83 to retain the upper end of the sleeve. A similar collar 87 at thebottom of the elastomeric sleeve has an annular rib 88 that retains thelower end of the sleeve. The collars 84 and 87 present radial shoulders89 and 90, respectively, at the upper and lower ends of the expansibleanchor assembly 91.

The outer segmented anchor element 92 is adapted to engage the casing 11and circumscribes a backing member 93. Annular grooves at the upper andlower inner surfaces of the elements 92 receive annular ribs 94 and950i" the backing member 93.

The segmented casing-engaging member 92 includes a central outer surfaceportion 96 which is parallel to the axis of the mandrel. Above thecentral portion 96 is a surface 97 that inclines inwardly toward theaxis at a shallow obtuse angle relative to the surface 96. Similarly, asurface 98 inclines inwardly at the same angle from the lower end of thecentral portion 96.

As a result of this construction, fluid under pressure entering throughopenings 99 and 100 in the mandrel exerts a force against the sleeve 83to expand the members 92 and 93 outwardly in the usual manner. This willurge the central portion 96 of the segmented member 92 flat against theinner wall of the casing 11. Pressure also will be exerted opposite theinclined surfaces 97 and 98 at the upper and lower portions of themember 92. This will tend to bend the member 92 about the points 101 and102 where the surfaces 97 and 98, respectively, connect with the centralportion 96. When the member 92 bends about the point 101, the upperinner corner 103 of the member 92 swings through an arc.'

Similarly, bending about the fulcrum 102 causes the lower inner corner104, to pivot through an arc. ternal pressures, therefore, cause the endportions 97 and 98 to approach alignment with the central outer surface,96 as the member 92 is bent. The effect is an elongation of the member92 as the arcuate movement of the corners 103 and .104 causes them tohave axial increments of travel. This elongation of the member 92compensates for the stretching of the mandrel 85, thereby preventing agap from opening up at the shoulders 89 and 90. As before, therefore,the sleeve 83 is retained and prevented from extrusion. ribs 94 and 95on the backing member 93 cause the backing member to elongate with themember 92 as the bending movement takes place, so that there will be nospace between the backing member and the casing-engaging member 92 wherethe sleeve 83 might enter.

It can. be seen, therefore, that the device of this invention can bemanufactured in different forms, while still retaining the advantageousfeature of the Zero clearance at the ends of theexpansible portion ofthe anchor during all operating conditions. Regardless of whichembodiment of the invention is utilized, the expansible sleeve is alwaysfully supported and can never be forced out of a gap under the influenceof the pressure within the anchor.

Having fully described my invention, it is to be understoodthat I do notwish to be limited to the details set forth above, but my invention isof the full scope of the f appended claims.

I claim:

1. In an anchor device for use within a well casing, the combination of:tubular body means including a mandrel adapted to be lowered into theWell casing, an elastomeric sleeve encircling said mandrel, acasing-engaging member disposed around said elastomeric sleeve andhaving a plur'ality of longitudinal slots defining a series ofcircumferentially adjacent gripping elements, shoulders on the tubularbody engaging opposite ends of said member to prevent longitudinalmovement thereof relative to said tubular body while permitting saidopposite ends of said member. to move in a radial direction, each slotextend- The in- The connections formed by the. annular beingcommunication between the interior of said mandrel and the interior ofsaid elastomeric sleeve, whereby fluid under pressure within saidmandrel may expand said elastomeric sleeve and cause it to expand saidbacking strips and said gripping elements, outward to engage saidgripping elements with the casing.

2. In an anchor device for use within a well casing, the

.co'mbination'of: a tubular body including amandrel adapted to belowered into the well casing, an elastomeric sleeve encircling saidmandrel, a casing-engaging member havinga plurality of longitudinalslots defining a series of circumferentially adjacent gripping elements,

shoulders on the tubular body engaging opposite ends of said member toprevent longitudinal movement thereof relative to said tubular bodywhile permitting said opposite ends of said member to move in a radialdirection, each slot extending from one end of said member andterminating short of the other end of said member, adjacent slotsextending from opposite ends of said member so that each grippingelement is joined at opposite ends to next adjacent gripping elements, aseries of circumferentially adjacent backing strips interposed betweensaid elastomeric sleeve and said casing-engaging member, said backingstrips being staggered with respect to said gripping elements to bridgethe slots and to prevent portions of said elastomeric sleeve frompassing into said slots, and a port in the mandrel establishing fluidcommunication between the interior of said mandrel and the interior ofsaid elastomeric sleeve, whereby fluid under pressure within saidmandrel may expand said elastomeric sleeve and cause it to expand saidbacking strips and said gripping elements outward to engage saidgripping elements with the casing.

3. In an anchor device for use within a well casing, the combination of:tubular body means including a mandrel adapted to be lowered into thewell casing, an elastomeric sleeve encircling said mandrel, acasing-engaging member disposed around said elastomeric sleeve andhaving a plurality of longitudinal slots defining a series ofcircumferentially adjacent gripping elements, a pair of retainer collarson the tubular body means clamping said member between them with freedomof the ends of said casing engaging member to move in the radialdirection, means on said collars securing the ends of said elastomericsleeve thereto, the tubular body means having a skirt, one of thecollars being mounted for axial sliding movement relative to saidtubular body means and having seal means slidably engaging said skirt,said one collar having a first surface means on one side of said sealmeans adjacent said casing-engaging member and a second surface means onthe opposite side of said seal means remote from said casing-engagingmember, said surface means being subject to fluid pressure for urgingsaid one collar in said axial sliding movement relative to said tubularbody, said second surface means being of greater area than said firstsurface means, whereby said one collar is urged toward saidcasing-engaging member by fluid pressure thereon, a series ofcircumferentially adjacent backing strips interposed between saidelastomeric sleeve and said casingengaging member, said backing stripsbeing staggered with respect to said gripping elements to bridge theslots and to prevent portions of said elastomeric sleeve from passinginto said slots, and means establishing fluid communication between theinterior of said mandrel and the interior therebetween and expansiblemeans interconnecting said engaging elements, said engaging elementsbeing radially movable between contracted and extended positions,

means for coupling said engaging elements to said mandrel in an axialload-supporting position yet permitting radial movement to saidcontracted and extended positions, said coupling means including meansfor contacting surfaces of said engaging elements at opposite ends ofsaid engaging elements, and maintaining said contact under operatingconditions of said device for confining said sleeve means and preventingextrusion outwardly thereof, backing means interposed between saidsleeve means and engaging means so as to be disposed over said spaces tobridge the same in said contracted and extended positions, and means forestablishing fluid communication to the interior of said sleeve meansfor application of pressure to said sleeve means.

5. A well tool for use in a well conduit comprising: a body member;anchoring means on said body member including conduit-engaging meansmovable relative to said body member between a retracted position and anexpanded position where said body member is held relative to a well boreconduit against movement axially thereof, said anchoring means includingan expansible sleeve member for actuating said conduit-engaging means,said body member having upper and lower cooperative abutment meansadapted for engagement with the adjacent ends of said conduit-engagingmeans and pressure-responsive means for bringing said upper and lowerabutment means into engagement with said ends.

6. In an anchor device for use within a well casing, the combination of:tubular body means having first and second oppositely directed abutmentmeans thereon spaced apart longitudinally and facing one another,pressureresponsive means on said body means between said spaced abutmentmeans comprising an elastomeric sleeve encircling said body means,laterally extensible casing-engaging means including circumferentiallyarranged longitudinally extending gripping elements around said bodymeans, said casing-engaging means having first and second opposedabutment surfaces thereon, respectively, facing an adjacent one of saidabutment means, sleeve-supporting means including circumferentiallyarranged longitudinally extending backing strips between said sleeve andcasingengaging means and circumferentially offset relative to saidgripping elements to bring each of said backing strips, respectively,into operative relationship to an adjacent pair of said grippingelements, and means for transmitting axial loads on said body means tosaid casing-engaging means including first and second members,respectively, slidably mounted on said body means above and below saidcasing-engaging means between said abutment means and abutment surfacesfor engagement therewith; and means establishing fluid communicationbetween the interior of said body means and the interior of said sleeve,whereby fluid under pressure may expand said elastomeric sleeve andbacking strips radially to extend said casingengaging means outwardlyinto engagement with the easing, at least one of said members having anarea responsive to pressure from fluid applied to said sleeve for urgingsaid one member inwardly against the adjacent abutment surface of saidcasing-engaging means for substantially eliminating clearance betweensaid one member and said' abutment surface through which said sleevecould extrude.

7. An anchor device for use within a Well casing comprising a bodyadapted to be lowered into a well casing,

an expansible sleeve circumscribing said body,

said body having passage means for receiving pressurized fluid,

said passage means communicating with the interior of said sleeve forproviding an outwardly directed force on said sleeve by said pressurizedfluid upon receipt of such pressurized fluid by said passage means ofsaid body,

a casing-engaging means around said sleeve,

said casing-engaging means being expansible outwardly in response to aforce thereon received from said sleeve as a result of the applicationof said pressurized fluid to the interior of said said sleeve,

said casing-engaging means having exterior surface portions forengagement with the interior of a Well casing upon such expansion ofsaid casingengaging means,

positioning means adjacent either end of said casingengaging means forpositioning said casing-engaging means longitudinally of said body,

and pressure-responsive means having a surface acted upon by fluidpressure, said pressure-responsive 10 means being associated with saidcasing-engaging means for substantially eliminating any clearancebetween said positioning means and said casing-engaging meansupon'application of fluid pressure to said body and said outwardexpansion of said casing-engaging means irrespective of longitudinalelongation of said body. 8. A device as recited in claim 7 in which saidcasingengaging means includes for said exterior surface portions aplurality of substantially longitudinally extending elongated segments,

each segment having a first outer surface portion substantially parallelto the axis of said body for initially engaging the interior of a Wellcasing upon said expansion of said casing-engaging means, and at leastone second outer surface portion longitudinally outwardly of said firstsurface portion intersecting said first surface portion at a relativelyshallow obtuse angle,

said segments being bendable about the intersection of said surfaceportions in response to fluid pressure applied thereto through saidsleeve, each of said segments having an inner corner at the end of saidsecond surface portion,

said corners being pivoted through an are upon such bending whereby saidsecond surface portions approach alignment with said first surfaceportions upon said bending and and the lengths of said segments areincreased in the direction of said axis of said said mandrel, saidpositioning means including a shoulder on said body at either end ofsaid casing-engaging means for engagement with said segments,

said segments upon said bending maintaining said engagement as a resultof the elongation thereof for thereby providing said means foreliminating clearance upon said longitudinal elongation of said body. 9.An anchor device for use within a well casing comprising a body adaptedto be lowered into a well casing, an expansible sleeve circumscribingsaid body,

said body having passage means for receiving pressurized fluid,

said passage means communicating with the interior of said sleeve forproviding an outwardly directed force on said sleeve by said pressurizedfluid upon receipt of such pressurized fluid by said passage means ofsaid body, an assembly around said sleeve,

said assembly including a casing-engaging means expansible outwardly inresponse to a force thereon received from said sleeve as a result of theapplication of said pressurized fluid to the interior of said sleeve,

said casing-engaging means having exterior surface portions forengagement with the interior of a well casing upon such expansion ofsaid casing-engaging means, each end portion of said assembly includingan assembly abutment, said body including a body abutment adjacent eachof said assembly abutments for cooperation with said assembly abutmentsto position said assembly longitudinally of said body and transmit loadsfrom said assembly to said body, and pressure-responsive meansassociated with said assembly for preventing substantially any clearancebetween adjacent abutments of said body and said assembly when saidcasing-engaging means is expanded outwardly by said sleeve irrespectiveof longitudinal elongation of said body. 10. An anchor device for usewithin a well casing comprising a tubular mandrel adapted to be loweredinto ,a Well casing, an expansible sleeve circumscribing said mandrel,

said mandrel having passage means from the interior to the exteriorthereof within said expansible sleeve,,

whereby pressurized fluid from said mandrel communicates with theinterior of said expansible sleeve for expanding said expansible sleeve,a segmented element circumscribing said expansible sleeve,

said segmented element being expansible by said expansible sleeve uponthe application of fluid pressure from'said mandrel to the interior ofsaid expansible sleeve, said segmented element having exterior surfaceportions for engagement with the interior of a well'casing upon suchexpansion for gripping said well casing and iesistingaxial movement ofsaid segmented element relative to said casing,

and means providing an outwardly extending shoulder at either end ofsaid segmented element for positioning said segmented elementlongitudinally of said mandrel,

at least one of said shoulders being provided by an annular axiallymovable member circurn-t scribing said mandrel axially outwardly of oneend of said segmented element, said annular member having pressure areameans responsive to fluid pressure on the interior of terior to theexterior thereof within said expansible sleeve,

whereby pressurized fluid from said mandrel communicates with theinterior of said expansible sleeve for expanding said expansible sleeve,

a segmented element circumscribing said expansible sleeve,

said segmented element being expansible-by said expansible sleeve uponthe application of fluid pressure from said mandrel to the interior ofsaid expansible sleeve,

said segmented element having exterior surface portions for engagementwith the interior of a well casing upon such expansion thereof forgripping said well casing and resisting axial movement'of said segmentedelement relative to said casing,

means providing an outwardly extending shoulder at either end of saidsegmented element'for positioning 1 said segmented elementlongitudinally of said mandrel,

at least one of said shoulders being provided by an axially .movableannular'member circum:

scribing said mandrel axially outwardly of one end of said segmentedelement,

said annular member having an outwardly facing circumferential surface,

said mandrel having an inwardly facing circumferential surfaceoverlapping said circumferential surface. of said annular member,

a seal for preventing the passage of fluid between said circumferentialsurfaces, and passage means for permitting fluid pressure on theinterior of said sleeve to be applied to said annular member outwardlyof said one end of said segmented element,

whereby said fluid pressure is contained by said seal and said annularmember provides a pressure area so that said fluid pressure produces areaction on said annular member forcing said annular member against saidone end of said segmented element.

12. An anchor device for use within a well casing comprising a tubularmandrel adapted to be lowered into a well casing,

an expansible sleeve circumscribing said mandrel,

said mandrel having passage means from the interior to the exteriorthereof within said expansible sleeve,

whereby pressurized fluid from said mandrel communicates with theinterior of said expansible sleeve for expanding said expansible sleeve,a segmented element circumscribing said expansible sleeve,

said segmented element being expansible by said expansible sleeve uponthe application of fluid pressure from said mandrel to the interior ofsaid expansible sleeve, said segmented element having exterior surfaceportions for engagement with the interior of a well casing upon suchexpansion thereof for gripping said well casing and resisting axialmovement of said segmented element relative to said casing, and meansproviding an outwardly extending shoulder at either end of saidsegmented element for positioning said segmented element longitudinallyof said mandrel,

at least one of said shoulders being provided by an axially movableannular member circumscribing said mandrel axially outwardly of one endof said segmented element,

said annular member having an annular inner shoulder, said mandrelhaving an annular fixed shoulder in opposed relationship with saidshoulder of said annular member, said sleeve having an annular ribinterposed between said shoulders of said annular member and saidmandrel,

whereby said fluid pressure on said sleeve reacts through said rib forexerting an axially inwardly directed force on said annular memberrelative to said segmented element for forcing said annular memberagainst said 'one end of said segmented element. 13. A device as recitedin claim 12 in which said adjacent shoulders of said annular member andsaid mandrel are inclined so as to be convergent outwardly in the radialdirection,

said rib of said sleeve being complementarily received in the spacebetween said adjacent shoulders.

14. An anchor device for use within a well casing comprising: a body; anexpansible sleeve encircling said body and fluidly sealed at itsopposite ends thereto; inner and outer tubular members encircling saidsleeve, each of said tubular members having a plurality of longitudinalslots 7 extending from opposite ends thereof and respectivelyterminating short of the other end thereof for making said tubularmembers radially expansible and defining interconnectedcircumferentially-spaced elements on each, said outer member having itssaid slots staggered in relation to said slots of said inner member forpreventing portions of said sleeve from entering said slots of saidouter member; means on said body engaging the opposite ends of saidouter member for substantially preventing longitudinal movement thereofin relation to said body without preventing radial movement of its saidends; and means establishing fluid communication with the interior ofsaid sleeve, whereby fluid under pressure may expand said sleeve andexpand said tubular members outwardly to bring the outer surfaces ofsaid elements of said outer member into engagement with a casing.

15. An anchor device for use in a well bore comprising: a mandrel havingport means; expansible sleeve means fluidly sealed around said mandreland port means; wallengaging means disposed over said sleeve means andarranged to move radially upon expansion and contraction of said sleevemeans and including means completely enclosing said sleeve means, saidwall-engaging means having exterior surfaces capable of engaging thewall of a well conduit in response to expansion of said sleeve means;and means for coupling said wall-engaging means on said mandrel forsupporting longitudinal loading on said mandrel including abutmentsurfaces adjacent opposite end portions of said wall-engaging means, andpressure-responsive means urging at least one of said abutment surfacesagainst one of said adjacent end portions of said wall-engaging meansfor confining said sleeve means and preventing extrusion thereof betweensaid one abutment surface and said adjacent one end portion.

'16. In an anchor device for use within a well casing, the combinationof: a body member; an elastomeric sleeve encircling said member;casing-engaging means comprising circumferentially-spaced,longitudinally-extending gripping elements around said sleeve; means formounting said gripping elements on said mandrel for preventing theirmovement axially relative to said mandrel while permitting said grippingelements to move in a radial direction, said gripping elements andmounting means having opposed surfaces arranged for abutting;pressure-responsive means for maintaining said opposed surfaces inabutment with one another for preventing extrusion of said elastomericsleeve between said abutting surfaces; circumferentially-space-d,longitudinally-extending backing means disposed between said elastomericsleeve and said gripping elements, said backing means beingcircumferentially staggered with respect to said gripping elements toenclose said elastorneric sleeve; and means establishing fluidcommunication between the interior of said mandrel and the interior ofsaid elastomeric sleeve, whereby fluid under pressure within saidmandrel may expand said elastomeric sleeve radially and cause it toexpand said backing means and said gripping elements outwardly to engagesaid gripping elements with a casing.

17. An anchor device for use within a well casing comprising: a bodyhaving passage means and adapted to be lowered into a well casing; anexpansible sleeve circumscribing said body, said passage meanscommunicating with the intrior of said sleeve; casing-engaging meansdisposed about said sleeve, said casing-engaging means being extendibleupon expansion of said sleeve for engagement with a well casing; meansadjacent the ends of said casing-engaging means for supporting saidcasing-engaging means longitudinally on said body; andpressure-responsive means having a surface acted upon by fluid pressure,said pressure-responsive means including means for substantiallyeliminating clearance between said supporting means and saidcasing-engaging means upon application of fluid pressure through saidpassage means to the interior of said sleeve.

18. An anchor device for use within a well casing comprising: a bodyadapted to be lowered into a well casing; an expansible sleevecircumscribing said body; said body having passage means communicatingwith the interior of said sleeve; an assembly around said sleeve, saidassembly including casing-engaging means extendible upon expansion ofsaid sleeve for engagement with a well casing, each end portion of saidassembly including an assembly abutment, said body including a bodyabutment adjacent each of said assembly abutments for cooperation withsaid assembly abutments to position said assembly longitudinally on saidbody and transmit axial loads from said body to said assembly; andpressure-responsive means for substantially preventing clearance betweenadjacent abutments of said body and said assembly when saidcasingengaging means are extended.

References Cited by the Examiner UNITED STATES PATENTS 1,343,273 6/1920Moore 279-2 2,373,005 4/1945 Baker 166122 2,767,676 10/1956 Johnson eta1. 26948.1 2,970,651 2/1961 Roberts l66212 CHARLES E. OCONNELL, PrimaryExaminer.

.T. A. LEPPINK, Examiner.

4. AN ANCHOR DEVICE FOR USE IN A WELL BORE COMPRISING: A TUBULAR BODYMEANS INCLUDING A MANDREL ADAPTED TO BE LOWERED INTO A WELL BORE, SAIDMANDREL BEING ADAPTED TO RECEIVE AN AXIAL LOAD IN EITHER DIRECTION,FLUID-TIGHT, PRESSURE-TRANSMITTING SLEEVE MEANS ENCIRCLING SAID MANDREL,LOAD-SUPPORTING, WELL BORE ENGAGING ELEMENTS CIRCUMFERENTIALLY DISPOSEDABOUT SAID SLEEVE MEANS WITH SPACES THEREBETWEEN AND EXPANSIBLE MEANSINTERCONNECTING SAID ENGAGING ELEMENTS, SAID ENGAGING ELEMENTS BEINGRADIALLY MOVABLE BETWEEN CONTRACT AND EXTENDED POSITIONS, MEANS FORCOUPLING SAID ENGAGING ELEMENTS TO SAID MANDREL IN AN AXIALLOAD-SUPPORTING POSITION YET PERMITTING RADIAL MOVEMENT TO SAIDCONTRACTED AND EXTENDED POSITIONS, SAID COUPLING MEANS INCLUDING MEANSFOR CONTACTING SURFACES OF SAID ENGAGING ELEMENTS AT OPPOSITE ENDS OFSAID ENGAGING ELEMENTS, AND MAINTAINING SAID CONTACT UNDER OPERATINGCONDITIONS OF SAID DEVICE FOR CONFINING SAID SLEEVE MEANS AND PREVENTINGEXTRUSION OUTWARDLY THEREOF, BACKING MEANS INTERPOSED BETWEEN SAIDSLEEVE MEANS AND ENGAGING MEANS SO AS TO BE DISPOSED OVER SAID SPACES TO